“how much are you spending on meta how much you spending on Tik Tok Google add all of that together and then look at how many people have done these kind of actions overall so how many installs have you got overall from every channel including organic.”

Measure Blended Cost Per Trial — Total Spend Divided by Total Trials Across All Channels

Post-ATT, per-channel ROAS is noisy at best and misleading at worst. Hannah's practical replacement: sum all paid channel spend, divide by total trials from every source including organic, and track that blended cost-per-trial over time. This captures the halo effect of ads on organic installs and prevents you from wrongly cutting a channel because its platform-reported numbers look bad.